Discussion:
In recent years, sialendoscopy has demonstrated effectiveness in avoiding sialoadenectomy, and therefore external approaches, in selected cases of obstructive and non neoplastic pathology3. In many of these cases, and in case of bulky intraductal palpable stones in the floor of mouth, the same results are obtained by transoral incision and removal.
However, in many cases of neoplastic pathology and chronic sialadenitis, sialoadenectomy remains indicated. With the advent of minimally invasive techniques, there has been a renewed interest in developing approaches that avoid visible scars, including robotic-assisted trans-hairline/retroauricular approaches (DOI: 10.1016/j.ijom.2012.04.008) and transoral robotic surgery (TORS)4. Yet, the “classical” transcervical approach remains the most validated and popular among head and neck surgeons, and the less demanding in terms of time and technology required. The submandibular degloving, always performed in the present series1, is a variant of the classical transcervical approach.
In table II results and complication rate among different sialoadenectomy techniques in different series are compared.
In the present series, the most relevant complication was the postoperative bleeding in a patient with a large (4.5 cm) benign tumor (pleomorphic adenoma); such large dimensions may be a contraindication to the described technique.
Another complication has been a surgical bed hematoma after the removal of the suction drain, associated with uncontrolled hypertension on the 6th postoperative day; it required the placement of a new suction drain and the adjustment of antihypertensive therapy, and confirmed our attitude, differently from some recent reports5, to always use suction drains to reduce the risk of postoperative haemorrhage and infection.
Benign tumours do not disrupt the capsular layer of the gland so that if the technique is carried out correctly the risk of spillage is supposed to be minimal. This assumption is confirmed by the fact that in the present series we recorded no recurrences among the benign tumors resected.
However, in the literature, the most relevant risk in submandibular gland surgery is the damage to the nerves lying in the area. The Hayes-Martin maneuver is the most adopted trick to spare the MMN. On the other hand, the main arguments of the advocates of the intraoral approach are that it avoids the cervical incision and, most of all, the dissection in close proximity to MMN itself. However, such approaches are associated with a higher risk of lingual and hypoglossal nerves injury and limitation in tongue movements6–89(see table II). In addition, intraoral dissection is difficult in chronically inflamed glands with severe adhesions to surrounding tissue, and conversion to the transcervical approach may be necessary8.
Because of such a markedly higher overall rate of nerve injury in transoral approaches, the transcervical approach remains the standard for submandibular sialoadenectomy. The present work is the first series of submandibular deglovings in the literature showing a neural complication rate (only two cases of transient nerve dysfunction in the present series) lower than the classical submandibular sialoadenectomy operation7,10–17. Such preliminary results, if confirmed on larger series, would support submandibular degloving, based on blunt subfascial and supracapsular dissection, sparing of the fascial layer and of vessels and nerves within it1, as a new standard for submandibular sialoadenectomy.